| Director | Chella, Chella Ayyavu |
|---|
Sathyamoorthy, alias Sakthi, is a laid-back constable in the Silukkuvarupatti police station who takes life too easy. Bhaskar is a new constable who is appointed by Sub-Inspector Muthaiya to assist Sakthi. Muthaiya keeps praising Sakthi nonstop due to the takes woven by Sakthi to score good points with him.
Cycle Shankar is a dreaded rowdy and don in Chennai. He is chased by Commissioner Panneerselvam after he murders a police officer in public, as the officer threatened to finish off Shankar. This starts a cat-and-mouse chase between the two. Rajeshwari, alias Raji, is Sakthi’s "love at first sight", which she does not reciprocate as he unknowingly insults her. Gradually, however, she warms up to him.
Minister Arumuga Perumal assigns Shankar the task of killing Nilakottai Narayanan without his henchmen. Shankar reaches a bar and settles down to have a drink. A couple of drunkards start to make a fuss, which turns into a full-blown riot. Added to the equation is Sakthi, who goes to the bar to have a half-boiled egg. While he goes to put the egg in his mouth, Shankar also simultaneously leaves and accidentally knocks the egg out of Sakthi's hand. Enraged, Sakthi beats up Shankar and throws him in jail, not knowing who he really is. In the melee, a thief steals Shankar's phone. Shankar's right-hand man Tony and Perumal keep calling the phone, leading to some hilarious scenes. Finally, Tony and his henchmen locate Shankar and get him released, but not before Shankar vows to kill Sakthi.
Sakthi meets Panneerselvam in disguise, who tells him to catch Shankar using the moniker "Operation Cycle". Sakthi, scared out of his wits, runs for his life. Meanwhile, Raji's father Ramalingam fixes an alliance for Raji as he is not happy with the idea of leaving his daughter a widow if Sakthi dies at the hands of Shankar. She then confronts Sakthi, who lies by saying that this is an undercover operation dubbed "Operation Cycle." Using this as an opportunity, and with the help of a dancer named Kanaka, Sakthi manipulates Shankar into kidnapping the groom and stops the marriage successfully. Tony also succeeds in kidnapping Narayanan and dumping him in the back of the truck, unbeknownst to Shankar. This leads to a car chase with Shankar chasing Sakthi and Raji, who are on a cycle; Narayanan's men chasing Shankar's men; and all chasing "Share Auto" Chandran.
Finally, Sakthi arrests Shankar, with the evidence of all those involved in the conspiracy getting released, and gets promoted to an SI, while Muthaiya gets suspended for six months by Superintendent A. Raghavan. The film ends with Sakthi marrying Raji, a phone call from Bhaskar telling Sakthi that Shankar has escaped from jail, and Raji (thinking that it is another undercover operation) indirectly telling Sakthi to capture Shankar again. On hearing this, Sakthi faints.